1. Field of the Invention
The present invention relates to a crank arm remover for a bicycle, and more particularly to a crank arm remover for a bicycle that is applicable to at least two different types of crank arm of a bicycle.
2. Description of the Prior Arts
Referring to FIG. 1, a conventional crank arm remover for a bicycle generally comprises a screw bolt 11 and a threaded sleeve 12. At an end of the screw bolt 11 is provided a corner portion 111 which is to be rotated and engaged by a grip handle 13. Another end of the screw bolt 11 is formed with an abutting block 112. The threaded sleeve 12 is provided on its outer surface with plural threads 121. The threaded sleeve is moveably installed on the screw blot 11 and located between the corner portion 111 and the abutting block 112. As shown in FIG. 2, to remove a crank arm of a bicycle, the user can start by screwing the threads 121 of the threaded sleeve 12 in a threaded hole 211 of the crank arm 21 and engaging the grip handle 13 with the corner portion 111 of the screw bolt 11, at this moment, the threaded sleeve 12 and the crank arm 21 are locked with each other, and then pushing the grip handle 13 so as to make the screw bolt 11 move toward the central rotation axis 22 until the abutting block 112 of the screw bolt 11 pushes against the central rotation axis 22. Thus causing the crank arm 21 to be pushed by the threaded sleeve 12 to move backward and finally disengage from the central rotation axis 22. However, this crank arm remover still has some disadvantages in real operation:
The threaded sleeve 12 needs to be locked with the crank arm 21 if want to remove the crank arm 21, and the abutting block 112 of the screw bolt 11 needs to move to and push against the end surface of the central rotation axis 22. However, there is another type of crank arm that the central rotation axis 22 and the crank arm 21 are screwed with each other, as shown in FIG. 3. This type of central rotation axis 22 and the crank arm 21 cannot be pushed by the abutting block 112 of the screw bolt 11 (namely, an axial hole 221 of the central rotation axis 22 is larger than the abutting block 112 of the screw blot 11), it needs to use another type crank arm remover to remove the crank arm, thus, the conventional crank arm remover for a bicycle is not so practical.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.